The apparatus and methods described herein relate generally to adjustment mechanisms between shafts, and in particular, to adjustment mechanisms between a pair of elongate, tubular shafts.
An adjustment mechanism can be used to adjust the relative position between two elongate, tubular shafts. One of the shafts may be at least partially slidable within the other of the shafts, with the adjustment mechanism positioned therebetween selectively engageable to substantially prevent relative sliding between the shafts.
A particular type of adjustment mechanism is used in an adjustable garment rack to permit adjustment of the height of a garment rod relative to a base. A pair of upstanding outer shafts are attached to the base. An inner shaft is slidable within each of the outer shafts. Positioned within the outer shaft and below a bottom end of the inner shaft is a roller. Attached to the bottom end of the inner shaft is a supplemental tube having a ramp integrally formed therewith. A thin rod extends through the inner shaft, connected at one end to the roller and at the other end to a button.
A spring biases the button, along with the attached thin rod, from an upper end of the inner shaft to cause the roller to ride up the ramp. As the roller rides up the ramp, it engages the inner wall of the outer shaft. The friction between the roller, the inner wall of the outer shaft, and the ramp attached to the inner shaft prevents relative movement between the inner shaft and the outer shaft. To allow relative movement between the inner shaft and the outer shaft, the button can be depressed against the biasing force of the spring to move the thin rod downwardly, causing the roller attached to the end of the thin rod opposite the button to ride down the ramp and away from the inner wall of the outer shaft.
Although functional, the garment rack adjustment mechanism described hereinabove disadvantageously tends to bind up, where depression of the button does not consistently result in movement of the roller down the ramp to permit relative sliding between the inner and outer shafts. As the roller and the ramp are positioned entirely within the outer shaft, access thereto when the adjustment mechanism is bound up is difficult.
Several factors cause the garment rack adjustment mechanism described above to bind up. One particular problem is when the thin rod becomes off-center, causing the roller to likewise become off-center on the ramp. The roller comprises two rotating wheel members, one on each side of an axle connected to the thin rod. The thin rod is significantly thinner than the inner diameter of the inner shaft. Thus, because the thin rod is only supported by a constriction at its upper extreme, its lower extreme having the roller attached can significantly move within the inner shaft and cause one of the rotating wheel members to be in greater frictional contact between the inner wall of the outer shaft and the ramp than the other, thereby causing the adjustment mechanism to bind up.
Another particular problem with the garment adjustment mechanism described above is the configuration of the ramp, which both contributes to the binding up of the mechanism and is costly to manufacture. The ramp is a separate tube that is attached to the end of the inner shaft. A portion of the tube is cut away at an inclined angle at one opening thereof, and a flat piece of sheet metal is cut into a curved profile and welded thereto. The piece of sheet metal only partially covers the opening in the supplemental tube, and the thin rod and attached roller project through the uncovered portion of the opening. Not only does such a complicated construction increase the cost of the adjustment mechanism, but it also results in a limited range of movement of the roller along the piece of sheet metal before the thin rod contacts the piece of sheet metal. For example, the roller travels only about 0.25 inches down the ramp, even though the ramp is about 1.25 inches in length, before the contact between the thin rod and the ramp lifts the roller from the ramp. When such contact occurs, the roller may lift off of the ramp and not properly engage both the sidewall of the outer tube and the ramp. Further contributing to the minimal travel of the roller along the ramp before the thin rod lifts it therefrom is the sharp angle of the ramp, which is about 23 degrees. If sufficient force is exerted on the roller to press it back down against the ramp, thereby bending the thin rod against the piece of sheet metal, the friction engagement between the roller, the ramp, and the inner wall of the outer shaft may be greater than desirable, which may result in binding of the mechanism and difficulty an adjusting the relative positions of the inner and outer shafts.
Further, the opening is sized to allow the roller to retreat thereinto, which can undesirably result in the roller becoming lodged within the inner tube. In addition, the entire thin rod can easily be withdrawn from the inner tube, contributing to both assembly and operational difficulties.
Problems with the above-described adjustment mechanism are increased when a pair of garment rack adjustment mechanisms are used, one for each of the pair of outer and inner shafts. When one of the adjustment mechanisms binds up and the other does not, or does so to a lesser degree, one of the pair of shafts slide relative to each other to a different extent that the other of the pair of shafts. This can further result in even more binding, as the skewing of one of the pair of shafts relative to the other of the pair of shafts can add to the likelihood of a bound adjustment mechanism.
There is provided a new improved method and apparatus for adjusting the relative position between a pair of elongate, tubular shafts using an adjustment mechanism. This is achieved by using a wedge element shiftable between a wedged position wherein relative movement between the pair of shafts is substantially prevented and an unwedged position permitting relative movement between the pair of shafts. In the wedged position, the wedge element is frictionally engaged between a ramp and an inner wall of one of the shafts. An actuator member, having a first end region attached to the wedge element and a second end region opposite therefrom, is operable to shift the wedge element between the wedged and unwedged positions to control the relative movement between the pair of shafts. Binding of the adjustment mechanism may be reduced by supporting the actuator member in more than one location to maintain desirable contact between the wedge element and the ramp and the inner wall of the one of the pair of shafts. Binding of the adjustment mechanism may also be reduced by providing for an increased range of movement of the wedge element along the ramp to prevent undesirable frictional engagement between the actuator member and the ramp. Further, a stop may be provided to substantially maintain the wedge element from unintentionally withdrawing into the inner shaft.
An apparatus is provided for adjusting the relative position between two elongate, tubular shafts. The apparatus includes an outer elongate tubular shaft having a diameter and an inside wall. Also included is an inner elongate tubular shaft having a diameter different from the diameter of the outer shaft in order to permit the inner shaft to be slidably received at least partially within the outer shaft. An adjustment mechanism comprising a wedge element, a ramp, and an actuator member is positioned to allow for adjustments in the relative positioning between the inner and outer shafts. A ramp is positioned within the outer shaft and has an inclined surface. The wedge element is rideable along the inclined surface of the ramp between the wedged position and the unwedged position. The wedge element is moveable between a wedged position, wherein it is disposed in frictional engagement between the inner wall of the outer shaft and the ramp, and an unwedged position generally removed from the inner wall of the outer shaft. The wedged positioned substantially prevents relative movement between in the inner and outer shafts. Conversely, the unwedged position of the wedge element permits relative movement between the inner and outer shafts. The actuator member is at least partially received within the inner shaft and is operably connected to the wedge element for shifting the wedge element along the inclined surface of the ramp between the wedged position and the unwedged position. The actuator member includes a first end region operably connected to the wedge element and a second end region opposite from the first end region. The first and second end regions of the actuator member are each substantially supported by supports effective to generally maintain the position of the actuator member relative to the inner shaft and the wedge element operably attached to the first end region of the actuator member to facilitate accurate shifting of the wedge element between the wedged position and the unwedged position.
The inner shaft may have an internal end disposed within the outer shaft and an opposite end disposed external of the outer shaft. The ramp may be connected to the end of the inner shaft disposed within the outer shaft, and the inclined surface of the ramp may be inclined downwardly away from the end region of the inner shaft.
The support at the first end region of the actuator member may comprise a slot that is formed in the ramp. The ramp may comprise a pair of opposing sidewalls having upper and lower edges. The lower edges of the sidewalls may be connected by a bottom wall. The upper edges of the sidewalls may comprise the inclined surface of the ramp. The ramp may comprise a piece of sheet metal that has been folded at the intersections of the sidewalls and the bottom wall thereof. The support at the second end region of the actuator member may comprise a centering member disposed on the external end of the inner shaft and having an aperture through which the actuator member is slidable.
A biasing mechanism may be operably connected to the actuator member to provide a biasing force urging the wedge element, operably connected to the first end region of the actuator member, toward the unwedged position, where relative movement between the inner and outer shafts is substantially prevented. The actuator member may have an actuator control operably attached to the second end region thereof and disposed external to the inner shaft. The actuator control may permit shifting of the actuator member, and the wedge element attached to the first end region thereof, against the biasing force of the biasing mechanism to shift the wedge element toward the unwedged position, whereby relative movement between the inner and outer shafts is permitted. The actuator member may have a flexible portion disposed between its first and second end regions. The flexible portion of the actuator member can allow for the actuator control attached to the second end region of the actuator member to be in a nonlinear alignment relative to the wedge element attached to first end region of the actuator member. Thus, the flexible portion allows for the actuator member to be operable within a curved or angled inner shaft.
A pair of the apparatus may be provided for use in an adjustable garment rack. The adjustable garment rack may include a base portion having the outer shafts of the apparatus disposed at opposite ends thereof in an upstanding manner. A garment hanging rod having the inner shafts of the apparatus disposed at opposite ends thereof may be spaced above the base member effective to permit use of the garment hanging rod for hanging garments. The spacing between the base portion and the garment hanging rod may be adjustable using the adjustment mechanism of the apparatus.
A method is provided of forming an apparatus for adjusting the relative position between two elongate, tubular shafts. The method includes providing an outer elongate tubular shaft having a diameter and an inside wall. The method further includes providing an inner elongate tubular shaft having a diameter selected to be less than the diameter of the outer shaft, thereby permitting the inner shaft to be at least partially slidably received within the outer shaft. The method further comprises positioning a ramp within the outer shaft and having an inclined surface on the ramp. The method also includes positioning a wedge element within the outer shaft. The wedge element is moveable along the ramp between a wedged position, wherein the wedge element is disposed in frictional engagement between the inner wall of the outer shaft and the ramp, and an unwedged position generally removed from the inner wall of the outer shaft. The wedge element is rideable along the inclined surface of the ramp between the wedged position and the unwedged position. When the wedge element is in the wedged position, relative sliding movement between the inner and outer shafts is substantially prevented. Conversely, when the wedge element is in the unwedged position, relative movement between the inner and outer shafts is permitted. The method also includes connecting an actuator member, at least partially received within the inner shaft, to the wedge element for shifting the wedge element along the inclined surface of the ramp between the wedged position and the unwedged position. The method further includes supporting a first end region of the actuator member, having the wedge element connected thereto, relative to the inner shaft with a first support. The method also includes supporting a second end region of the actuator member, opposite the first end region, relative to the inner shaft with a second support. The use of the first and second supports assists in maintaining the alignment of the actuator member to relative to the inner shaft in order to generally maintain the positioning of the wedge element for correct shifting thereof between the wedged and unwedged positions.
The inner shaft may have an internal end disposed within the outer shaft and an opposite end disposed external of the outer shaft. The method may include the step of connecting the ramp to the end region of the inner shaft, positioned within the outer shaft, and downwardly inclining the inclined surface of the ramp away from the end region of the inner shaft.
The step of supporting the first end region of the actuator member with a first support may additionally include the step of forming a slot in the ramp and aligning at least a portion of the first end region of the actuator member within the slot. The method may also include forming the ramp by folding a piece of sheet metal to have a pair of opposing sidewalls, where the opposing sidewalls have upper and lower edges. The lower edges of the sidewalls may be connected with a bottom wall.
The method may also include the step of supporting the second end region of the actuator member with a second support, including the step of attaching a centering member to the inner shaft and aligning at least a portion of the second end region of the actuator member within an aperture in the centering member. By aligning the first and second end regions of the actuator member with the supports, the position of the actuator member within the inner tube may be generally maintained for facilitating accurate shifting of the wedge element between the wedged and unwedged positions.
The method may also include the step of operably connecting a biasing mechanism to the actuator member to provide a biasing force urging the wedge element, operably connected to the first end region of the actuator member, toward the wedged position. The method may also include the step of attaching an actuator control to the second end region of the actuator member. The actuator control may be disposed external to the inner shaft in order to permit shifting of the actuator member, and the wedge element attached to the first end region thereof, against the biasing force of the biasing mechanism in order to shift the wedge element to the unwedged position. The method may also include providing the actuator member with a flexible portion disposed between the first and second end regions thereof. The flexible portion may permit the actuator control attached to the second end region of the actuator member to be in nonlinear alignment relative to the wedge element attached to the first end region of the actuator member. The flexible portion thus allows for control of the wedge element using the actuator control when the inner tube is curved or has bends therein.
An apparatus is provided for adjusting the relative position between two elongate, tubular shafts. The apparatus includes an outer elongate, tubular shaft having a diameter and an inside wall. The apparatus further includes an inner elongate, tubular shaft having a diameter selected to be less than the diameter of the outer shaft, thereby permitting the inner shaft to be slidable at least partially within the outer shaft. Wedge means are positioned within the outer shaft. The wedge means are shiftable between a wedged positioned substantially preventing relative movement between the inner and outer shafts and an unwedged positioned substantially permitting relative movement between the inner and outer shafts. Actuator means for shifting the wedge means between the wedge position and the unwedged position are also provided. The actuator means may have a first end region and a second end region opposite the first end region. First support means effective to generally maintain the position of the first end region of the actuator means are provided. Further, second support means effective to generally maintain the position of the second end region of the actuator means are also provided. The use of the first and second support means combine to generally maintain the positions of the actuator means, and the wedge means attached thereto, relative to the inner tube for controlling the position of the wedge means.
An adjustable garment rack is also provided. The adjustable garment rack includes a base having a pair of upstanding tubular outer shafts attached to opposing end regions thereof. A pair of upstanding tubular inner shafts are each slidably received within the outer shafts. A garment rod extends between the upstanding inner shafts and are spaced a distance from the base. An adjustment mechanism is provided between each of the inner and outer shafts in order to permit adjustment of the relative positioning between the inner and outer shafts to adjust the distance between the garment rod and the base. The adjustment mechanism includes a ramp attached to the inner shaft and positioned within the outer shaft. An actuator member having one end attached to a wedge element slidable along the ramp is also provided. The wedge element is slidable along the ramp between a wedge position wherein the wedge element substantially prevents relative movement between the inner and outer shafts in an unwedged position permitting relative movement between the inner and outer shafts. The actuator member is biased by a biasing mechanism to shift the wedge element to the wedged position. The actuator member is shiftable against the biasing force of the biasing mechanism to shift the wedge element to the unwedged position. A pair of supports are positioned to generally maintain the alignment of the actuator member relative to the inner shaft. By maintaining the alignment of the actuator member, the wedge element attached to the one end of the actuator member can more precisely be maintained in the proper position within the outer shaft.